1. Field of the Invention
This invention relates to a liquid coating machine of a rotary screen printing press or the like.
2. Description of the Related Art
In screen printing by a rotary screen printing press, ink is placed in a screen printing forme, and the screen printing forme is pressed against paper by a squeegee or a doctor roller to transfer the ink to a printing surface of the paper through the openings of the screen printing forme. The screen printing forme needs to be replaced each time a different printing product is to be printed.
The work of replacing the screen printing forme will be described, for example, in connection with an intaglio and rotary screen printing press as shown in FIG. 6.
In this printing press (liquid coating machine), sheets of paper (sheets, for short) W are fed one by one from a feeder 10 onto a feedboard 11. Then, the sheet W is passed from a swing arm shaft pregripper 12 on to a transfer cylinder 13, and then gripped by grippers 14a of an impression cylinder 14 for the purpose of transport (transport means). On the other hand, conventional inks are supplied from within ink fountains 20 to chablon rollers 17 via ink fountain rollers 19 and intermediate rollers 18, and supplied to an ink collecting cylinder 16 (other device). Then, the inks are collectively supplied to an intaglio plate of a plate cylinder 15. Also, special ink is directly supplied, in a constant amount in a predetermined pattern, from within a rotary screen cylinder (stencil printing cylinder) 22 to the intaglio plate of the plate cylinder 15 via a rubber roller 21 (liquid coating unit).
These inks have their surplus amounts removed by a wiping roller 23, and are then transferred to the sheet W passed on to the impression cylinder 14 for the purpose of printing. The printed sheet W is transported and delivered by a delivery chain 26 via a delivery cylinder 25.
In such a rotary screen printing press, when the screen printing forme (stencil printing plate) of the rotary screen cylinder 22 is to be replaced, it has been common practice for two operators to hold opposite end portions of the screen printing forme in places near entrances 28 to the machine. This is because a forme or plate replacing work space S for replacing the screen printing forme of the rotary screen cylinder 22 has its upper side closed with a printing unit or a transport unit for the sheet W, and has its fore-and-aft direction restrained by other printing devices. Thus, the space S is only a narrow space defined by these printing devices. Moreover, the machine entrances 28 formed on both sides of a machine frame 27 are narrow. These situations make it difficult for one operator to do replacing work while holding the screen printing forme.
Thus, the two operators have to do the work in a well-coordinated manner with an unnatural posture, thus posing the problems of decreasing the operators' work efficiency and imposing a burden on the operators.